Table of Contents
Advertisement
Portable Generator Familiarization & Troubleshooting Guide
Section 2 • Generator Components & Systems
Two-Pole Rotors:
A 2-pole rotor has a single north and a single south
magnetic pole. One revolution of the 2-pole rotor creates a
single cycle of alternating current flow in the stator windings.
To determine the rotor speed required for a given (AC)
frequency, use the following formula:
RPM = Desired Frequency times 60
Hertz: The complete set of values through which an
alternating current (AC) repeatedly passes.
Example: An alternator with a 2-pole rotor must produce
a USA standard of 60 Hertz.To find the required driven
speed of the rotor, multiply 60 times 60 to obtain 3600.The
required driven speed of of the rotor is 3600 RPM.
Four-Pole Rotors:
A 4-pole rotor has two south and two north poles.These
rotors provide the same frequency as the 2-pole rotor, but
at half the driven speed of the 2-pole rotor (Figure 2.3).
Figure 2.3 — Typical 2-Pole And 4-Pole Rotors
Stator Assembly
The word "stator" means stationary winding. A voltage or
electromotive force (EMF) is induced into the stator by the
action of rotating the magnetic field created by the rotor. A
typical stator assembly is shown in Figure 2.4. Stators differ
greatly, depending on the ratings and design of the specific
alternator on which they will be used.
Figure 2.4 — Typical Stator Assembly
Typical stators may contain:
• An "excitation" winding (DPE)
• An (AC) "power" winding
• A "battery charge winding" (BCW)
A "single voltage" stator (AC) power winding schematic is
shown in Figure 2.5.
Figure 2.5 — Single Voltage, 1-Phase Stator Winding
It consists of a single winding, capable of supplying 120VAC
only to a panel receptacle.
21
Hide quick links:
Advertisement
Table of Contents
